Field of the Invention
The present invention relates to a tricycloundecylamine and acid addition salts thereof. More particularly, the present invention relates to 1-amino-tricyclo[4.3.1.1.sup.2,5 ] undecane of the formula (I) and acid addition salts thereof: ##STR1##
The new compounds of the present invention, i.e. 1-aminotricyclo [4.3.1.1.sup.2,5 ] undecane and acid addition salts thereof have an excellent effect of inhibiting propagation of Newcastle disease virus of Paramyxo viruses belonging to the group of RNS viruses, in embryonic cells of chickens and the toxicity thereof to the cells is relatively low. Namely, the compounds of the invention inhibit the propagation of the virus even if they are used in a low concentration of about one-third the concentration of adamantylamine hydrochloride which is effective for the same purpose. Adamantylamine hydrochloride is a well-known antiviral substance against influenza. The compounds of the invention are thus useful substances as active ingredients of medicines for human beings and animals.
Elementary analysis and mass spectrum analysis of the new compound of the present invention, i.e. 1-aminotricyclo [4.3.1.1.sup.2,5 ] undecane (I), and acid addition salts thereof indicate that they are compounds containing only one nitrogen atom. Further, the structures of these compounds have been confirmed from the facts that absorptions peculiar to the amine group (3325, 3250 cm.sup.-1) are shown in the infrared absorption spectrum and the substitution position of the starting material used for the synthesis of (I), i.e. 1-acetylaminotricyclo [4.3.1.1.sup.2,5 ] undecane, is the 1-position.
The compound of formula (I) of the present invention can be synthesized by hydrolysis of the corresponding N-acetylated compound, i.e. 1-acetylaminotricyclo [4.3.1.1.sup.2,5 ] undecane of formula (II): ##STR2##
The hydrolysis can be carried out under any reaction conditions effective for general alkaline hydrolysis of amides. In other words, the desired 1-aminotricyclo [4.3.1.1.sup.2,5 ] undecane of formula (I) can be obtained by hydrolyzing 1-acetylaminotricyclo [4.3.1.1.sup.2,5 ] undecane of formula (II) in an aqueous solution of an alkali or in the presence of an alkali in an alcohol or a mixture of water and an alcohol as solvent. As the alkali used for the hydrolysis, there can be mentioned alkali metal hydroxides such as sodium hydroxide and potassium hydroxide and alkali metal carbonates such as sodium carbonate and potassium carbonate. The alcohols include lower alcohols such as methanol, ethanol and propanol and glycols such as ethylene glycol, propylene glycol and diethylene glycol. The reaction temperature is in the range of 10.degree. to 350.degree. C, preferably 60.degree. to 300.degree. C, more preferably 170.degree. to 245.degree. C.
The acid addition salts of the formula (I) compound are obtained easily by neutralization of the thus-obtained compound of formula (I). The acids used include mineral acids such as hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, thiosulfuric acid and phosphoric acid and organic acids such as p-toluenesulfonic acid, formic acid, acetic acid, propionic acid, oxalic acid and citric acid. Among those acids, hydrohalogenic acids such as hydrochloric acid, hydrobromic acid and hydroiodic acid are convenient and preferred.
1-Acetylaminotricyclo [4.3.1.1.sup.2,5 ] undecane of formula (II) used as the starting material in the present invention can be obtained easily by, for example, reacting a 2-halogenotricyclo [4.3.1.1.sup.2,5 ] undecane, 1-hydroxytricyclo [4.3.1.1.sup.2,5 ] undecane or endo-1-hydroxymethyl-exo-2,3-trimethylenenorbornane with acetonitrile in the presence of sulfuric acid.
The following examples further illustrate the present invention. Processes for the synthesis of the starting material are also shown in the Preparations.